Of these,
15 were not up to scratch and four were described as ‘woeful’, with
problems including mismatched lenses and failure to meet the
prescription supplied by the testers.

In addition, five companies sent
pairs of varifocal lenses that were regarded as ‘potentially very
dangerous’.

In these cases, the suppliers guessed at the distance between the pupils
of the customer, rather than asking for accurate measurements.

More people are opting for online purchases from websites such as Goggles4U rather than the routine store-bought frames

Which
said: ‘If lenses like these are not positioned accurately, the glasses
could be unsafe when driving and using stairs.’

The organisation added that a 69 pair of varifocals from a company
called Goggles4U was ‘extremely dangerous’, adding: ‘The incorrect
prescription and different heights of the optical centres would have
been likely to cause headaches and eye strain as well as making the
glasses unsafe, for example, when driving.’

Goggles4U rejected the criticism, saying that its website advises
customers to ask their ‘eye doctor’ for pupil distance measurements
before ordering.

Those with a simple, low prescription have a better chance of receiving
an acceptable pair, Which found.

Of the nine ‘standard’ pairs tested,
eight were approved by the researchers. The ninth pair, supplied by
Vision2U, were for the wrong prescription.

Which said: ‘Our experts’ verdict was that anyone with a simple
prescription might be fine buying online, but they would have
reservations about those with higher or more complex prescriptions.’

Four firms were praised for offering to send frames to try at home
before buying: Direct Sight, Glasses123, Glasses Direct and Glasses
Frames and Lenses.

Which also found that many websites are selling contact lenses without
valid prescriptions. This is illegal, as online sellers must confirm
that a buyer has a valid prescription before supplying contacts.

Testers contacted 15 suppliers but 13 ignored this rule. Only Asda and The Contact Lens Shop asked for a prescription.